Hydraulic air-compressor.



Patented 1an. 23, |900.

3 Sheets--Sheet l.

A TTOHN m 2 N .1. 1| ,l W. u 3 I sa W 3 o 2 1 F l,

l.. E. MITCHELL. HYDRAULIC AIR COMPRESSOR.

(Application filed July 13, 1899.)

(No Model.)

m: News Pcrans co, PHoTuumo.. wAsHmmou, p. c.

No. 641,98l. Patented 1an. 23, |900.

L. E. MITCHELL.

HYDRAULIC AIR COMPRESSOR.

(Application filed July 13y 1899.)

(No Model.)

3 Sheets-Sheet 2.

gw /NENTOH A TTOHNE Y S ma mams Pasns co, wmauno.. wAsHxNnToN, u. c

Patented 1an. 23, i900.

3 Sheets-Sheet 3.

A TTOHNEYS L. E. MlTcHELL. HYDRAULIC AIR COMPRESSOR.

(Application filed July 13, 1899.)

(No Model.)

W/ T/VE SSE S 'me Ncnms Psreas co. pHoro-mmc wAsHlNmou. u. c.

'lUNrrEn STATES PATENT OFFICE.

LEE E. MlTCHELL, OF BOSTON, MASSACHUSETTS.

HYDRAULIC AIR-COMPRESSOR.

SPECIFICATION forming part of Letters Patent No. 641,981, dated January 23, 1900.

Application led .Tuly 13, 1899. Serial No. 723.690. (No model.)

To @ZZ whom t may concern: which are located at the lower end of the cyl- Beit known thatl,LEE E. MITCHELL,of Bosinder, the same being contained within a secon, in the county of Su ffolk and State of Mastion B, which is preferably screw-threaded to 55 sachusetts,haveinvented a new and Improved the lower end of the cylinder A, the joint be- 5 Hydraulic Air-Compressor, of which the foltween the two being made tight by means of lowing is a full, clear, an dexact description. a packing-ring a3. To the lower end of the My invention relates to an improvementin section B is screw-threaded the base C, which air-compressors actuated by means of a hyhas a chamberltherein,serving to receive the 6o draulic cylinder and comprises the novel feawater which passes to and from the opposite ro tures hereinafter described and claimed. end ofthe power-cylinder A, said chamber be- Reference is to be had to the accompanying ing connected with one end of a pipe Y, said drawings, forminga part of this specification, pipe being connected to the upper and lower in which similar characters of reference indiends of the power device by means of unions 65 cate corresponding' parts in all the iigures. l2 and short nipples, which connect, respecr5 Figure 1 is a side elevation of my device tively, with the chamber I and the upper end complete, showing the water and air cylinof the cylinder A. ders. Fig. 2 is a sectional side elevation of When the device is used as an air-comthe same. Fig. 3 is asectional side elevation presser, the piston a will have a hollow pis 7o of the lower portion of the hydraulic cylinder, ton-rod a, which passes through a stuffing zo showing the valve'reversing piston and the box a4 into the air-compressing cylinder A', valves by which it is controlled. Fig. 4 is a where it is connected with theair-compressing similarsectional elevation showing the valves piston a2. The admission and discharge of in dierent positions. Fig. 5 is a sectional air to and from the aircompressing cylinder 75 side elevation of the lower portion' of the hy- Aare controlled by means of check-valves K,

25 draulic cylinder, showing the water inlet and 7c, K2, and K3, connected, respectively, to opdischarge valves and the piston by which they posite ends of the cylinder by means of nipare actuated. Fig. 6 is a similar elevation ples K4 and Kand connected with each other"n showingthepartsinadifferent position. Fig. by means of a pipe K. This mechanism is 8o 7 is a sectional plan taken upon the line 7 7 only one of many forms which may be used 3o in Fig. 3. Fig. 8 is a sectional plan taken for this purpose, and as it does not form any upon the line 8 8 in Fig. 5, and Fig. 9 is a essential part of my present invention willl sectional side elevation of the pipes and valves not be described in further detail. Said connecting the opposite ends of the air-cylmechanism is of such a character as to freely 85 inder. i admit air to opposite ends of the cylinder 35 The principal object of my invention is to through the check-valves 7o and K3 and to produce a hydraulic cylinder and its valve discharge the same through the check-valves mechanisms which are automatically oper- K and K2. ated, so that the piston willcontinue recipro- The section B, which contains the valve 9o cation until shut oit by some outside means, mechanism for controlling the admission and 4o said device being especially adapted for use discharge of water, has two end diaphragms in compressing air. It is, however, evident or partitions B and B2 and a central vertical that the hydraulic cylinder and its mechanpartition B3, which divides the section B into isms may be used for any form of power purtwo chambers S and lV, said chambers being 95 poses, the compressing of air being only one respectively the supply and waste-water or 45 of many uses to which it may be put. discharge chambers. The vertical partition lVhile the device is described as used in B3 is swelled in the center, so as to form a connection with an air-compressor, it is to be cylinder B4, which contains a piston D, by understood that the hydraulic portion of the which the main water admission and disloo device may be used for any power purpose. charge valves are actuated. In the upper dia- 5o The power portion of the device herein phragrn B are formed two apertures leading, shown consists of a cylinder A, havinga pisrespectively, into the supply and Waste-waton c therein, and the valve mechanisms ter chambers and adapted to receive plugs E E2, which form valve-seats and passages for the water. These plugs have a hollow center, through which pass the Water and the valve-stems d2 d5. The lower end of the upper plug E is faced off, so as to form a valveseat which acts in connection with the valve d, said valve being provided with a leather or similar facing. washer d. The upper end of the upper plug E or the end which projects within the cylinder has a diaphragm E', closing the same, said diaphragm being provided' with a hole which is concentric with the hole in the plug through which the water passes, said hole in the diaphragm E acting as a guide for the rod or stem (Zito which the valve d6 is secured. The water isdischarged from the main passage in the plug E through lateral passages e, which communicate therewith and with the interior of the cylinder A.

The plug vE is the one through which the water passes when admitted from the supplychamber S to the cylinder A. The plug E2, which is upon the opposite side of the cylinder, is somewhat similar in construction, but is reversed in position, and, together with the valve d, controls the discharge of the water from the cylinder A. This plug E2 has acentral waterpassage, a diaphragm E3, which in this .casel is on the lower end of the plug or that end which projects into the waste-Water cham-ber W, and it is provided with late ral passages e for the discharge of water. These plugs are preferably threaded, so'as to screw d into the openings in the diaphragme BVB? "which directly engages the valve-seat.

The upper ends of both plugs are of slightlygreater diameter than` thethreaded portion, so as-to form a stop Alimiting the downward motion of the plugs when screwed to place.

The valve d, which controls the discharge of water from one end of the cylinder, is' similar in construction tothe valve d6 and provided with a'leather or similar washer d', This A valve is mounted upon a stem or rod d2, said stem and the stem d5 being connected with a cross head or bar D2, sothat both stems are moved together.'

The two valves just described control the admission and discharge of water to and from one end only of the cylinder. Similar valves Z7 and cl3 are provided for controlling the admission and discharge of water to andfrom the opposite end of the cylinder. These valves are, however, placed in the lower diaphragm B2. A The plugs E and E2, whichk form the seats for the lower valves, are exactly the samel in construction as the corresponding plugs placed in the upper diaphragm B'. These water-controlling valves are actuated by means of the piston D, which is mounted within the cylinder B4, located concentric with the power-cylinder A. The lower end of the cylinder B4 is closed by a screw-th readed` plug b and the upper end by a plug h, which is also provided with a central hole for the piston-rod D and with a suitable packing means for said piston-rod.

valves will move together.

The water is admitted to and discharged from the cylinder B4 through ports f3f4 and g? g4, located in opposite ends and upon opposite sides ot' the cylinder. These ports are controlled by means of valve-cylin ders F and G, which contain piston-Valves, two pistonvalves being provided for each of the cylinders, the cylinder F containing piston-valves F and FQ-and the cylinder G containing piston-valves G' G3, each of the valves in said cylinders controlling the port in its respective end of thecylinder B4. Each of the valvec'ylinders F and G is provided with a central cut or notch F4 and G4, respectively, which permits communication between the valvecylinders and the supply and waste-water chambers, respectively.

The .pistons G' and G3, which control the admission of water to the cylinder B4, are both mounted upon a common rod or stem G2, and the piston-valves F and F2, which control the discharge of water from the cylinder B4,'are mounted upon a common rod or stem F3, both of these rods being connected with a cross head or bar I-I, so that all of the piston- The valves are directly actuated by the reciprocation of the power-piston a. The cross-head H has a rod H centrally connected.theretoand extending within the hollow piston-rod ct. The rod H' has a nut or collar hsecured to its upper end and forming a tappet, said nut or collar being of such a size as to slide freely in the bore ofV the rod a', but being larger than the aperture in the piston a, through which the rod H reciprocates. The piston a in its downward travel will ultimately strike the crosshead I-I andmove it downward, carrying the piston-valveswith it. In its upward movement the piston will ultimately strike the collar or tappet h and carry the rod H' and cross-head H, together with the piston-valves', upward. These two movements are relied upon to move said valves, so as to admit and discharge waterto and from opposite ends of the cylinder B4, containing the valve-shifting piston. y

The valve-cylinder G, through which water is admitted to the valve-shifting cylinder, is provided with longitudinally-extending grooves g, (clearly shown in Figs. 3, 4, and 7,) said grooves extending from the central notch G4 a part only ot' the distance to the ports g3 and g4. When either of the piston-valves G' and GS is so placed that itoverlaps these lon-v gitudinal grooves, as is the case with the piston-valve G' in Fig. 4t, water can escape from the supply-chamber S through these ports to the opposite side kof the piston-valve, thus permitting, in the position shown in Fig. 4,

the water to be admitted to the upper end ot' ICO IIO

forcing the piston D upward. The water is discharged through the valve-cylinder F, and in this cylinder the longitudinal grooves f, which are similar in construction to the grooves g in the other valve-cylinder, are placed at the ends of the cylinder and communicate with the ports]03 and f". In the position shown in Fig. 3 water is being admitted to the lower side of the piston D and being discharged from the upper side thereof. In the position shown in Fig. e water is being admitted above the piston D and discharged from beneath the same. The operation of the device is as follows: In the position of the parts shown in Fig. 4 wateris being admitted to the upper side of the piston D,which forces the same downward and forces downward the water-controlling valves d6, C17, d, and d3. This closes the water-discharge valve CZ from the lower end of the cylinder and opens the water-discharge valve d3 connected with the upper end of the cylinder. It also opens the water-supply valve d6 connected with the lower end of the cylinder and closes the water-supply valve di connected with the upper end of the cylinder. The water-supply is thus admitted to the lower end of the cylinder and discharged from the upper end, forcing the piston a upward. lVhen the piston a reaches the upper limit of its travel, it strikesthe washer or tappet h, pulling upward the. cross-head H, thus shifting the piston-valves from the position shown in Fig. -l tothatl shown in Fig. 3. This reverses the direction of flow of the water through the cylinders F and G, ad mit-ting the supply through the port g4 to the lower end of the cylinder B'L and discharging the water at the upper portion of the same piston through the port f3 into the waste-water chamber. This causes the piston D to rise, carrying the water-controlling valves with it, thus reversing their position to that shown in Fig. 5 and discharging the water from the lower end of the cylinder A and admitting the water through the chamber I and pipe I to the upper end of the cylinder A. This device will continue in the same order of operations until the water-supply is `cutofl' or the air-pressure becomes suflcient to prevent its motion.

This device is adapted to a wide range of work, as the relative area of the water and air cylinders may be varied and made such as desired. It is thus possible to use water of high pressure economically for producing compressed air of low pressure or to use water of low pressure to produce compressed air of high pressure.

Having thus fully described my invention, I claim as new and desire to secu re by Letters Patentl. A hydraulic pumping-cylinder, having in one end supply and waste-water chambers provided oppositely with ports communicating with opposite ends of the power-cylinder, connected supply and waste-water valves adapted to control the flow of water through said ports to and from the power-cylinder, a shifting cylinder having a piston connected with said valves, a plurality of valve-chambers alongside of and parallel with the shifting cylinder, shifting valves movable in said chambers and controlling the shifting piston and tappet connections for moving said shifting valves from the power-piston at each end of its stroke, substantially as described.

2. A hydraulic pumping-cylinder having in one end supply and waste-Water chambers provided oppositely with ports communicating with opposite ends of the power-cylinder, connected supply and waste valves adapted to control the flow of water through said ports, a shifting cylinder having a piston connected with said valves, valve-cylinders located alongside the shifting cylinder and connected therewith, shifting valves in said cylinders movable parallel with the power-piston to control the shifting piston, a hollow rod for the power-piston, a rod slidable in said hollow rod, means whereby said rod is moved by the power-piston at each end of its stroke, and connections from the rod to the shifting valves, substantially as described.

3. A hydraulic pumping-cylinder, having in one end supply and waste-water chambers provided oppositely with ports communicating with opposite ends of the power-cylinder, connected supply and waste valves adapted to control the flow of water through said ports, a shifting cylinder having a piston con nected with said valves, two valve-cylinders lying. alongside the shifting cylinder and connected therewith by ports at their ends, one of said cylinders and its valves controlling the water-supply to the shifting cylinder, and the other controlling the waste-water discharge therefrom, said valve-cylinders having respectively a supply and waste connection with their central portions, the supplycylinder having longitudinal grooves or ports in its central port-ion communicating with its supply-opening and the waste or discharge cylinder having similar grooves or ports within each end connecting with the ports leading from the shifting cylinder, two connected piston-valves in each cylinder adapted when reciprocated to alternatelyuneover the longitudinal ports or grooves, and means for moving them from the power-piston, substantially as described.

4. In a hydraulic power-cylinder, a valveshifting cylinder and piston and valve mechanism controlling the shifting piston, comprising two valve-cylinders lying alongside 0f the shifting cylinder and communicating therewith by ports at each end, said valvecylinders having respectively a supply and. a waste-water connection with the central portion thereof, and longitudinal grooves or ports lying respectively in the central portion of the supply-cylinder and communicating with the supply-opening thereof and at the ends of the Waste-cylinder and communicating with 'the shifting-cylinder ports, and two con- IIO nected piston-valves in each cylinder adapted when reciprocated to uncover diagonallyopposite grooves, and externallyoperated means for shifting said valves, substantially as described.

5. 'A hydraulic power cylinder and piston, the cylinder having at one end a section having alongitu dinally-extending partition forming supply and waste-water chambers, and provided with a central circular chamber forming a shifting cylinder, the supply and waste-water chambers having ports at one end connecting directly with one end of the powercylinder and at the other end communicating by a pipe with the other end of the powercylinder, valves controlling said ports, a piston in the shifting cylinder and connected with said valves, auxiliary or shifting Valves controlling-the shifting piston and connections whereby said valves are adapted to be operated by the power-piston, substantially as described.

6. Ahydraulicpumping-cylinderhaving in one end supply and waste-water chambers each provided lwith ports communicating respectively with opposite endsof the cylinder, supply and waste-water valves controlling said ports, a shifting cylinder, a piston in said cylinder a cross-head carried at the upper freevend of the shifting piston-rod, the stems of said supply and exhaust Valves being connected with the cross-head, shifting valves controlling the shifting piston, and connections whereby said shifting valves are moved from the power-piston at each end of its stroke, substantially as described.

7. A hydraulic pumping-cylinder provided v with a'power-piston having a hollow pistonrod, the said cylinder having in one end supply and waste-water chambers provided oppositely with 'ports communicating with opposite ends of'the power-cylinder, connected supply and waste-water valves adapted to control the low of Water through said ports to and from the power-cylinder, a shifting cylinder having a piston connected with said valves, shifting valves movable at opposite sides of the shifting cylinder and controlling the shifting piston, a cross-head connecting the stems of the shifting valves and a rod connected with the cross-head and adapted to slide in the hollow rod of the power-piston, the movement of said rod and the parts connected therewith being controlled by the movement of the power-piston, substantially as described'.

8. The combination with a hydraulic cylinder having' in one end supply and waste-water chambers provided oppositely with ports communicating with opposite ends of the powercylinder, of connected supply and waste-water valves adapted to control the liow of water through said ports, a shifting cylinder having a piston connected with said Valves, shifting valves movable alongside of and parallel with said shifting cylinder and controlling the shifting piston, a hollow rod for the power-piston, an air-compressing cylinder into which said hollow rod extends, the said rod carrying the air-compressing piston, a rod slidable in` said hollow rod, and provided at its ends vwith-means adapted to be engaged by the power-piston at each end of its stroke, and a cross-head carried by said rod and connected with the stems of the shifting Valves, substantially as described.

9. In a hydraulic power-cylinder, a supply and a waste-water chamber in one end of said cylinder, each chamber being' provided with a port at each end having a valve-seat, the

' ports at opposite ends of the chambers cornmunicating with opposite ends of the powercylinder, the valve-seatsfor the ports of one of said chambers being located within the chamber and facing each other, andthe Valveseats for the ports of The other chamber being located at the outside of the chamber, and facing in opposite directions, a valve for each port the said valves being adapted to control the liow of water through said ports to and from the power-cylinder, a chamber between the supply and waste-water chambers, the said chamber forming a shifting cylinder, a piston in said shifting cylinder and connected with the said valves, and means for controlling the shifting piston, substantially as described.

LEE E. MITCHELL. 

